Research On Integrated Enery-saving Technologied Of Large-scale UHP-EAF Steelmaking

The EAF steel making technology has been developed rapidly in recent years. The major technical index and economical data of EAF operation have met the international standard, although some still needs to be improved. Energy-saving is definitely the trend for the development of EAF processing. Under the condition of energy shortage there is an urgent need to conduct a thorough research on energy-saving of EAF. This paper presents the research work of a comprehensive technology on the EAF energy-saving with the data from the operations of a large-scale ultra-high power electric arc furnace that was put into operation at TPCO in 1992. Based on the experiences of both domestic and abroad in EAF energy-saving, especially those in TPCO, we have examined the high efficiency EAF processing and the control theory. Through full utilizing the transformer's ability, enhancing the oxygen supply, increasing the aux energy input and optimizing the existing charging structure, we have invented a comprehensive energy-saving technology without changing the profile of the furnace and the transformer capacity. This technology will increase the production of EAF steelmaking and decrease the power consumption remarkably.This paper is concerned with several key technologies as follows:(1) Optimization of power supply:Three hundred thousand data were obtained with the on-line measurement of several electric operating parameters of the EAF steelmaking process using an apparatus with 0.2% measurement error. A reactance model (nonlinear), electric property plot and its pie chart are all established from the measured results. A general guideline of the working points and the power supply curve are also provided. All of these have been well applied in production.(2) Optimization of EAF charging structure:The paper also studied the effect of charging containing a great deal of DRI on the major technical index of EAF steelmaking process and provided the method to evaluate the rationality of charging structure. Based on the data from 1383 heats of EAF operation, the effect of charging structure on steelmaking process is examined and the...